Ink container with improved ink flow

ABSTRACT

An ink container includes a housing, a print head, and a fluid chamber. The housing has two inclined walls formed to divide the fluid chamber into a center ink well and two side ink wells. The housing also has two side walls, each having an inclined inner surface. The center ink well is formed between the two inclined walls. Each side ink well is formed between an inclined wall and a side wall. The inner surface of each side wall has a greater inclination than those of the inclined walls, so that each side ink well has a width decreasing from top to bottom.

BACKGROUND OF INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an ink container, and moreparticularly, to an ink container with improved ink flow.

[0003] 2. Description of the Prior Art

[0004] Please refer to FIG. 1. FIG. 1 is a sectional view of an inkcontainer 10 according to U.S. Pat. No. 6,042,225. The ink container 10comprises a housing 12, a print head 16, and an ink chamber 23 that isformed inside the housing 12 and includes a center ink well 22, and twoside ink wells 24. Each one of the three ink wells 22, 24 is employed tostore ink of one color in a porous member 26 such as a foam, whichabsorbs ink. The ink container 10 further comprises a center ink pipe 28and two side ink pipes 32. The center ink pipe 28 fluidly connects thecenter ink well 22 and the print head 16. The side ink pipe 32 connectsthe side ink well 24 and the print head 16. A center filter 30 ishorizontally installed on a top end of the center ink pipe 28 forfiltering ink transmitted from the center ink well 22, and each of twoside filters 34 is vertically installed between the side ink well 24 andthe corresponding side ink pipe 32 for filtering ink transmitted fromthe side inkwell 24.

[0005] Due to a capillary attractive force, ink is kept inside the smallhole of the porous member 26 such that the porous member 26 is able toabsorb and store ink. This is equivalent to providing negative pressureinside the ink wells 22, 24, and the negative pressure force overcomesgravity acting on the ink, so as to reduce the fluid pressure inside theink pipes 28,32. This prevents ink from leaking outside the print head,so that the printed document is not contaminated. However, on the otherhand, if the capillary attraction is strong, the fluid pressure insidethe ink pipes 28, 32 becomes too low to provide enough pressure forejecting ink from the print head 16, so that print quality is affected.In a worst case, ink is locked in the ink wells 22, 24 and is unable toflow into the ink pipes 28,32.

[0006] In other words, the fluid pressure inside the ink pipe 28, 32must be kept in a proper range, such that ink is ejected from the printhead 16 when the print head 16 is printing and ink does not leak outsidethe print head 16 when the print head 16 is not printing.

[0007] According to the prior art, the side ink well 24 has a narrowertop end (W3<W4), so that the top end of the porous member 26 iscompressed more than its bottom end. This gives ink inside the side inkwell 24 a trend to be pulled up and such a trend resists ink flowingfrom the top end to the bottom end.

SUMMARY OF INVENTION

[0008] It is therefore a primary objective of the present invention toprovide an ink container that improves ink flow from top to bottom.

[0009] In a preferred embodiment, the present invention provides an inkcontainer comprising a housing having two side walls, each side wallhaving an inner surface, a print head installed at a bottom of thehousing for ejecting ink onto a document, and an ink chamber formedinside the housing having two inclined walls for dividing the inkchamber into a center ink well and two side ink wells. The center inkwell is formed between the two inclined walls and has a width decreasingfrom top to bottom, each of the two side ink wells is formed between aninclined wall and a corresponding side wall. The inner surface of atleast one of the side walls has a greater inclination than that of thecorresponding inclined wall, so that the side ink well formed betweenthe side wall and the inclined wall has a width decreasing from top tobottom.

[0010] The present invention further provides an ink container thatcomprises a housing having two side walls, a print head installed at abottom of the housing for ejecting ink onto a document, snd an inkchamber formed inside the housing having two inclined walls for dividingthe ink chamber into a center ink well and two side ink wells. Thecenter ink well is formed between the two inclined walls and has a widthdecreasing from top to bottom. Each of the two side fluid wells isformed between an inclined wall and a corresponding side wall. The inkcontainer further comprises a porous member positioned inside one of theside fluid wells for absorbing ink, and the porous member has a widthincreasing from top to bottom.

[0011] It is an advantage of the present invention that the bottom endof the porous member is compressed more than the top end, so as toimprove ink flow from top to bottom.

[0012] These and other objectives of the present invention will no doubtbecome obvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment which isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0013]FIG. 1 is a sectional view of an ink container according to theprior art.

[0014]FIG. 2 is a sectional view of an ink container according to thepresent invention.

[0015]FIG. 3 is a perspective view of a porous member of an inkcontainer according to a second embodiment.

DETAILED DESCRIPTION

[0016] Please refer to FIG. 2. FIG. 2 is a sectional view of an inkcontainer 50 according to the present invention. The ink container 50comprises a housing 52 that has two side walls 54, each of which has aninner surface, a print head 56 that is installed at a bottom of thehousing 52 for ejecting ink onto a document, and an ink chamber 63 thatis formed inside the housing 52 and has two inclined walls 60 fordividing the ink chamber 63 into a center ink well 62 and two side inkwells 64. The center ink well 62 is formed between the two inclinedwalls 60 and has a width decreasing from top to bottom. Each of the twoside ink wells 64 is formed between an inclined wall 60 and acorresponding side wall 54. The inner surface of at least one of theside walls 54 has a greater inclination than that of the correspondinginclined wall 60, so that the side ink well 64 has a width decreasingfrom top to bottom. Each of the three ink wells 62, 64 is employed tostore one color of ink by way of a porous member 66, such as a foam thathas a uniform width, to absorb ink.

[0017] The ink container 50 further comprises a center ink pipe 68 andtwo side ink pipes 72. The center ink pipe 68 fluidly connects thecenter ink well 62 and the print head 56. The side ink pipe 72 connectsthe side ink well 64 and the print head 56. A center filter 70 ishorizontally installed on a top end of the center ink pipe 68 forfiltering ink transmitted from the center ink well 62. Two side filters74 are installed between the side ink well 64 and the corresponding sideink pipe 72, so that the width of the bottom portion of the side inkwell 64 also decreases from top to bottom (W9>W10).

[0018] According to the present invention, the widths of the center inkwell 62 and the side ink well 64 decrease from top to bottom, so thatthe bottom portion of the porous member 66 with uniform width iscompressed more than the top portion. This causes ink inside the inkwell to have a trend of being pushed down, and such a trend improves inkflow from the top end to the bottom end.

[0019] Please refer to FIG. 2 again, where the center ink well 62 withwidth decreasing from top to bottom (W5>W6) can be formed naturally inthe molding process. Considering the side ink well 64, a rib 58 withwidth increasing from top to bottom is added to the inner face of theside wall 54 so as to form the side ink well 64 with width decreasingfrom top to bottom (W7>W8).

[0020] Please refer to FIG. 3. FIG. 3 is a perspective view of theporous member 82 according to a second embodiment. An ink container usedto contain the porous member shown in FIG. 3 is the same as the inkcontainer 10. The only difference is the porous member 82 that isinstalled in the side ink well 24. The porous member 82 has a widthincreasing from top to bottom (W13<W14). Moreover, the width differencebetween top portions of the side ink well 24 and the porous member 66 isless than the width difference between bottom portions of the side inkwell 24 and the porous member 82(W13-W3<W4-W4), such that the bottomportion of the porous member 82 is compressed more than its top portion.This also causes ink inside the ink well to exhibit a trend of beingpushed down, and such a trend improves ink flow from the top end to thebottom end.

[0021] In contrast to the prior art, the present invention comprises theporous members 66, 82, whose top portions are compressed more than theirbottom portions, so as to improve ink flow from top to bottom.

[0022] Those skilled in the art will readily observe that numerousmodifications and alterations of the device may be made while retainingthe teachings of the invention. Accordingly, the above disclosure shouldbe construed as limited only by the metes and bounds of the appendedclaims.

What is claimed is:
 1. A fluid container comprising: a housing havingtwo side walls each having an inner surface; a print head installed atbottom of the housing for injecting fluid onto a document; and a fluidchamber formed inside the housing having two inclined walls for dividingthe fluid chamber into a center fluid well and two side fluid wells, thecenter fluid well being formed between the two inclined walls and havinga width decreasing from top to bottom, the two side fluid wells eachformed between an inclined wall and a corresponding side wall; whereinthe inner surface of at least one of the side walls has a greaterinclination than that of the corresponding inclined wall so that theside fluid well formed between the side wall and the inclined wall has awidth decreasing from top.
 2. The fluid container of claim 1 furthercomprising porous members positioned inside the center fluid well andthe two side fluid wells for absorbing fluid.
 3. The fluid container ofclaim 1 further comprising a center fluid pipe formed between the centerfluid well and the print head for connecting the center fluid well andthe print head.
 4. The fluid container of claim 3 further comprising acenter filter horizontally installed on a top end of the center fluidpipe for filtering fluid transmitted from the center fluid well.
 5. Thefluid container of claim 1 further comprising two side fluid pipes eachformed between a side fluid well and the print head for connecting theside fluid well and the print head.
 6. The fluid container of claim 5further comprising two side filters each installed between a side fluidwell and a corresponding side fluid pipe for filtering fluid transmittedfrom the side fluid well.
 7. The fluid container of claim 1 wherein thecenter fluid well and the two side fluid wells are used to store ink ofthree different colors.
 8. A fluid container comprising: a housinghaving two side walls; a print head installed at bottom of the housingfor injecting fluid onto a document; a fluid chamber formed inside thehousing having two inclined walls for dividing the fluid chamber into acenter fluid well and two side fluid wells, the center fluid well beingformed between the two inclined walls and having a width decreasing fromtop to bottom, the two side fluid wells each formed between an inclinedwall and a corresponding side wall; and a porous member positionedinside one of the side fluid wells for absorbing fluid inside the sidefluid well, the porous member having a width increasing from top tobottom.